Concrete floors are common today in large, medium and small retail stores, manufacturing and production facilities, warehouses, automotive shops and service centers, shopping centers, sidewalks, garages, commercial buildings and residential basements. The strength of concrete provides the durability and rigidity required in these environments. However, the exterior surface of a newly poured concrete floor, once dry, is often rough, uneven, and provides a dull appearance. Furthermore, when left in this unfinished state, the concrete will inherently produce dust particles from the constant scuffing, whether it is from foot traffic or wheeled traffic that can build over time and become a nuisance to those who work and/or live in these environments. It is well known to first grind the concrete surface and then coat the surface with a sealant to smooth the concrete, to make it aesthetically pleasing to the eye, and to help reduce dust particles.
In the grinding process, commonly used grinding machines usually have a planetary or direct drive belt and gear drive systems containing a plurality of circular drive plates mounted to gears on a deck with removable abrasive pads attached to each drive plate. These grinding machines may also be referred to as grinding, honing, abrasive or abrading machines. They may also be referred to as polishing and cleaning machines. Hereinafter, the term “grinder” is used in the generic sense and includes abrasion, scrubbing, sweeping, honing, grinding, sanding and/or abrading, cleaning and polishing. These types of machines can also be referred to as an apparatus for treating a floor surface. The term “treating a floor surface” as used herein can mean either cleaning, abrading, sanding, scrubbing, grinding, polishing, or honing a floor surface. These polishing and cleaning machines may typically be electric walk along machines where an operator stands behind the machine and pushes it along at a certain pace such that the deck sufficiently grinds, abrades, hones, polishes and or cleans the floor surface.
While walk along configurations and ride-on configurations have both been used, they both generally cannot be used to grind or sand close to an edge of the floor surface where a wall, molding or shelf stands extend vertically upward. As a result, smaller edge grinders have been developed to treat the floor surface next to any vertical wall or unit. These units are generally smaller than a fall grinder or polisher and may have a single grinder disc where the disc protrudes out of a housing or deck. Presently known constructions for edge grinders pose several problems. Firstly, the rotation of the single disc produces a torque on the entire machine which produces fatigue in the operator and makes it harder for the operator to control the machines. More aggressive treatments of floors such as abrading and sanding exert signified torque which can quickly fatigue an operator who is working hard to control the machine. In addition, the exposed edge of the disc may engage and gouge the wall or side molding if the operator does not adequately control the machine.
What is needed is a floor edge grinder that reduces or eliminates the torque on the operator and provides a safeguard to prevent the disc from gouging any wall or side molding.